Fay R R
Parmly Hearing Institute and Department of Psychology, Loyola University, Chicago, IL 60626, USA.
J Assoc Res Otolaryngol. 2000 Sep;1(2):120-8. doi: 10.1007/s101620010015.
This study investigates the effects of spectral separation of sounds on the ability of goldfish to acquire independent information about two simultaneous complex sources. Goldfish were conditioned to a complex sound made up of two sets of repeated acoustic pulses: a high-frequency pulse with a spectral envelope centered at 625 Hz, and a low-frequency pulse type centered at 240, 305, 390, or 500 Hz. The pulses were presented with each pulse type alternating with an overall pulse repetition rate of 40 pulses per second (pps), and a 20-pps rate between identical pulses. Two control groups were conditioned to the 625-Hz pulse alone, repeated at 40 and 20 pps, respectively. All groups were tested for generalization to the 625-Hz pulse repeated alone at several rates. If the two pulse types in the complex resulted in independent auditory streams, the animals were expected to generalize to the 625-Hz pulse trains as if they were repeated at 20 pps during conditioning. It was hypothesized that as the center frequency of the low-frequency pulse approached that of the 625-Hz pulse, the alternating trains would be perceived as a single auditory stream with a repetition rate of 40 pps. The group conditioned to alternating 625- and 240-Hz pulses generalized least, with maximum generalization at 20 Hz, suggesting that the animals formed at least one perceptual stream with a repetition rate of 20 pps. The other alternating pulse groups generalized to intermediate degrees. Goldfish can segregate at least one "auditory stream" from a complex mixture of sources. Segregation can be based on spectral envelope and grows more robust with growing spectral separation between the simultaneous sources. Auditory stream segregation and auditory scene analysis are shared among human listeners, European starlings, and goldfish, and may be primitive characteristics of the vertebrate sense of hearing.
本研究调查了声音的频谱分离对金鱼获取关于两个同时出现的复杂声源的独立信息能力的影响。金鱼被训练对由两组重复声脉冲组成的复杂声音做出反应：一组高频脉冲，其频谱包络以625赫兹为中心，另一组低频脉冲，其中心频率分别为240、305、390或500赫兹。每种脉冲类型交替出现，整体脉冲重复率为每秒40次脉冲（pps），相同脉冲之间的重复率为20 pps。两个对照组分别被训练对单独的625赫兹脉冲做出反应，重复率分别为40 pps和20 pps。所有组都接受了对以几种速率单独重复的625赫兹脉冲的泛化测试。如果复杂声音中的两种脉冲类型产生了独立的听觉流，那么预计动物会将其泛化到单独重复的625赫兹脉冲序列，就好像它们在训练期间以20 pps重复一样。据推测，随着低频脉冲的中心频率接近625赫兹脉冲的中心频率，交替的脉冲序列将被视为一个重复率为40 pps的单一听觉流。被训练对625赫兹和240赫兹交替脉冲做出反应的组泛化最少，在20赫兹时泛化最大，这表明动物形成了至少一个重复率为20 pps的感知流。其他交替脉冲组的泛化程度处于中等水平。金鱼能够从复杂的声源混合物中分离出至少一个“听觉流”。分离可以基于频谱包络，并且随着同时出现的声源之间频谱分离的增加而变得更加稳健。听觉流分离和听觉场景分析在人类听众、欧洲椋鸟和金鱼中都存在，可能是脊椎动物听觉的原始特征。
